It is now a known fact that flies are attracted to lighter colors, such as white, beige, cream, etc... Do you have alot of flies nesting on the eaves of your home? If so, the best you can do is to have broadcast applications around the foundation and eaves to reduce the population in the area. And then of course, when winter sets in, nature will take care of itself.
Interesting. I've never looked for "nesting flies"..in fact I've never heard of it..........but what you are saying is making sense because where the worst problem with them outside is where all the awnings are and so they get in every time a door is openned or there is a tear in a screen.
About winter setting in and nature taking it's course - of that I am aware!!!!!
My apologies, I did not mean to hijack your thread (but I just couldn't resist)